Naked Science Forum

General Science => General Science => Topic started by: Pseudoscience-is-malarkey on 01/11/2023 09:35:34

Title: Why do candy bars thaw quickly?
Post by: Pseudoscience-is-malarkey on 01/11/2023 09:35:34
When taken out of the freezer (the only good way to eat them I think) you have a good five minutes to devour them before becoming soft and boring to eat.
Title: Re: Why do candy bars thaw quickly?
Post by: vhfpmr on 01/11/2023 11:02:58
What are candy bars in this context?

Apart from temperature difference, there are three things that determine the rate at which something will thaw out: size, specific heat, & latent heat.

Size.
The amount of energy required to melt something is proportional to its mass which is proportional to volume, but the rate at which heat can enter it via the surface is proportional to the area of that surface. As the size of an object increases the volume increases with the cube of the dimensions, but the surface area only increases with the square, so large objects will have a higher mass to surface area ratio and will therefore take longer to thaw than smaller ones.

Specific Heat.
Is the name for the amount of energy required to raise the temperature of a specified amount of material by a specified temperature: the higher the specific heat the more energy it will take to raise its temperature, and the longer it will take to absorb that energy.

Latent Heat of Liquefaction.
Is the energy required per unit mass to change phase from a solid to a liquid (and LH of vaporisation from liquid to gas), so just like specific heat, the higher this figure is, the longer it will take to absorb enough heat to melt.

Find the mass, surface area, specific heat and latent heat for the ingredients your candy bar is made of, and you'll have the answer to your question.

Perhaps you've noticed that the bars are melting fast compared to ice? Well, the specific heat and latent heat of water are one of the highest of all materials, so if you compare it with other materials it will often be the slowest to thaw.
Title: Re: Why do candy bars thaw quickly?
Post by: alancalverd on 01/11/2023 11:05:31
I can't speak from experience of having become soft and boring etc but candy bars contain a lot of sugar and fat so have a lower freezing point and latent heat of solidification than pure ice.
Title: Re: Why do candy bars thaw quickly?
Post by: Bored chemist on 01/11/2023 14:13:01
Candy bars typically have melting points at or near 37C.

So they aren't doing any "thawing" when you take them out of the freezer.

Because there's no phase change, there's no need to transfer latent heat.
And with less heat to transfer the transfer is faster.
Title: Re: Why do candy bars thaw quickly?
Post by: alancalverd on 02/11/2023 17:21:41
Candy Barr featured in several  gentlemen's entertainment films in the 1970s but they may be considered soft and boring by modern standards.
Title: Re: Why do candy bars thaw quickly?
Post by: paul cotter on 02/11/2023 19:21:22
Aha, so you are a connoisseur of such material? Tut tut Alan.
Title: Re: Why do candy bars thaw quickly?
Post by: Pseudoscience-is-malarkey on 04/11/2023 15:34:05
Because there's no phase change, there's no need to transfer latent heat.
If this is true, how do you explain their texture change?
Title: Re: Why do candy bars thaw quickly?
Post by: alancalverd on 04/11/2023 18:16:30
Softening of a liquid is not a phase change, just a reduction in viscosity.
Title: Re: Why do candy bars thaw quickly?
Post by: Bored chemist on 04/11/2023 19:10:36
Because there's no phase change, there's no need to transfer latent heat.
If this is true, how do you explain their texture change?
Ask a blacksmith.
Title: Re: Why do candy bars thaw quickly?
Post by: Petrochemicals on 04/11/2023 21:59:52
Aha, so you are a connoisseur of such material? Tut tut Alan.
Maybe Paul, but it maybe a reference to his star turn as a leading man.
Title: Re: Why do candy bars thaw quickly?
Post by: alancalverd on 05/11/2023 08:42:05
Have you come to calibrate my MRI machine?
    Yes, ma'am. What seems to be the problem?
The magnet has ripped all the buttons off my clothes and the escaping helium has made me feel very friendly
    All in a day's work, my dear.
Is that a 3-axis magnetometer or are you just pleased to see me?
    Let's start with your Region Of Interest......

[Director].....ad lib euphemisms and double-entendres, fade to pink and play "Je t'aime" one more bloody time....don't we have any other records, FGS? 


Title: Re: Why do candy bars thaw quickly?
Post by: Petrochemicals on 05/11/2023 14:26:19
Have you come to calibrate my MRI machine?
    Yes, ma'am. What seems to be the problem?
The magnet has ripped all the buttons off my clothes and the escaping helium has made me feel very friendly
    All in a day's work, my dear.
Is that a 3-axis magnetometer or are you just pleased to see me?
    Let's start with your Region Of Interest......

[Director].....ad lib euphemisms and double-entendres, fade to pink and play "Je t'aime" one more bloody time....don't we have any other records, FGS? 



I was thinking more "carry on tromboning" with barbera windsor
Title: Re: Why do candy bars thaw quickly?
Post by: Bored chemist on 05/11/2023 14:49:36
If "tromboning" isn't a euphemism for something then it probably should be.
If it is a euphemism for something, I can probably live without knowing what.
But in any event, I wonder if a thread about candy is the best place for stuff that's less "family friendly" than most.
Title: Re: Why do candy bars thaw quickly?
Post by: Pseudoscience-is-malarkey on 05/11/2023 15:32:57
Softening of a liquid is not a phase change, just a reduction in viscosity.
I was about to report you to the British Physicist Guild or something for making up a scientific word until I found out it is an actual word.
Title: Re: Why do candy bars thaw quickly?
Post by: Bored chemist on 05/11/2023 16:11:04
Softening of a liquid is not a phase change, just a reduction in viscosity.
I was about to report you to the British Physicist Guild or something for making up a scientific word until I found out it is an actual word.
Softening?
Title: Re: Why do candy bars thaw quickly?
Post by: Kryptid on 06/11/2023 05:16:18
A word of warning: don't put a Snickers bar in the freezer. I broke a filling that way.